Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/8180
Title: A Comprehensive Model of Morphologically Realistic Cosmic Dust Particles: An Application to Mimic the Unusual Polarization Properties of the Interstellar Comet 2I/Borisov
Authors: Halder, Prithish
Sengupta, S
Keywords: Comets
Interstellar objects
Coma dust
Polarimetry
Radiative transfer simulations
Issue Date: 10-Apr-2023
Publisher: American Astronomical Society
Citation: The Astrophysical Journal, Vol. 947, No. 1, 1
Abstract: The cosmic dust particles found in space are mainly porous aggregates of smaller grains. Theoretically, these aggregates are replicated using fractal geometry, assuming a cluster of spheres. Although the light scattering response of cosmic dust aggregates has been thoroughly studied using clusters of spherical grains in the past few decades, the effect of irregularities on the surface of each grain in an entire aggregate has mostly been neglected. We introduce, for the first time, a visually realistic cosmic dust model that incorporates a mixture of rough fractal aggregates (RFA) and agglomerated debris (Solids) to replicate the unusual polarization–phase curve observed in the case of the interstellar comet 2I/Borisov at multiple wavelengths. The authenticity of the RFA structures has been verified by replicating light scattering results of circumstellar dust analogs from the Granada Amsterdam Light Scattering Database. We demonstrate that the light scattering response from the RFA structures has a very close resemblance to the experimental values. Finally, we model the observed polarization–phase curve of the interstellar comet 2I/Borisov using a mixture of RFA and solid particles. The best-fit data indicate the presence of a higher percentage of porous RFA structures (80%) owing to the fact that the comet carries a higher percentage of small and highly porous pristine cosmic dust particles. Further, the model indicates that the unusually steep polarimetric slope and the high dust-to-gas ratio in newer comets are mainly due to a higher porous-to-compact ratio
Description: Open Access
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
URI: http://hdl.handle.net/2248/8180
ISSN: 1538-4357
Appears in Collections:IIAP Publications



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